package com.alex.program;

public class 两两交换链表中的节点 {

    public static void main(String[] args) {

    }

    public ListNode swapPairs(ListNode head) {
        ListNode dummy = new ListNode(-1, head);
        while (head != null) {

            head = head.next;
        }

        return dummy.next;
    }
}
